Lifting machinery



Ju'ne ,2,r 1%)31l F; :auwlzy1,807,780

LIFTING MACHINERY, ESPECIALLY FQR THE ENDS OF PIVOT BRIDGES Filed Aug. 2, 1929 2 shew-sheet 1 Fig. 2

June 2, 1931. F. DuwE 1,807,780

LIFTING MACHINERY, ESPECIALLY FDR THE ENDS 0F' PIVOT BRIDGES Patented June 2, 1931 UNITED STATES FRIEDRICH DUWE, OF MAINZ-KASTEL, GERMANY, VASSIGrNOIB. TO MSCHINENFABRIK AUGSBURG-NRNBERG A. G., F N UREM MANY BERG, Gnlnivinivmn coRoRA'rioN or GEB.-

LIFTING- MACHINERY, ESPECIALLY FOR THE ENDS OF PIVOT :BRIDGES Application led August 2, 1929, Serial No.

My invention relates to lifting machinery for raising big loads a short distance, as, for instance, in the case of a pivot bridge, the ends of which, after they have'been removed .15 from their supports, have to be raised again to traiiic level, after -the bridge has again been closed. u

The object of the invention is to provide a specially constructed lifting machinery resulting in certain advantages not heretofore obtained. h

In accordance with this invention two eccentric discs movable along a horizontal path are used as a bearing for a supporting roller arranged between'them and which upon said discs being rotated is thereby moved to a raised position in which it supports the load.

The supporting roller is preferably carried by rollers mounted on said eccentric discs, so that only a rolling friction occurs and the discs may be actuated by means of thrust-rods. In this manner, the device operates very efficiently. Moreover, the rolling path of the eccentric discs extends a little beyond the point at which the highest eccentric position is reached, and at the endhof said path the supporting roller after passing the highest position of the eccentrics is slightly lowered so that the load is taken up by a fixed bearing and all the other parts are relieved.

On the accompanying drawings illustrating the invention, Fig. l is a side view ofv the lifting machinery and Fig. 2 a top-plan view thereof. Fig. 3 is on a smaller scale a diagrammatic' side view showing the new lifting machinery in position underneath one end of a pivot-bridge.

At' a are shown two circular discs having eccentrically arranged round bores provided with roller-bearings b, through which pass the trunnions 0 of a supporting roller cl placed between said discs, but being spaced therefrom. This roller is in the shape of a sector, but may also be a full-sized roller. Pins f mounted on the circumference of the discs a and projecting outwardly are engaged by thrust-rods g which are operated by means of racks L. The latter being pro- 3i82,946, and in Germany August 13, 1928.

vided with rollers ,le (Figs. l and 2) are moved t'o and fro in guidesz' bythe shaft Z by means of the pinions m; The outer faces of the discs a guided on the smooth tracks r by means of rims a provided on the inner faces of the discs (Figs. l and 2) are provided with toothed sectors n meshing with racks 0 arranged adjacent the tracks r.

In the inoperative position of the lifting machinery indicated in dotted lines in Fig. 1, roller l lies approximatelyl in the horizontal middle plane of the eccentric discs a, in which position it is resting on the buffer s. If now the discs a are moved by means of t-he thrustrods g in the direction of the arrow, roller (Z is gradually moved upward, until it bears with its circumference against the rail u Xed to the bottom face of the main bridge-girder t. Thile the eccentric discs continue to move,

roller d because of its frictional contact with the rail u rolls upon the latter and assumes the position shown in Fig. l in full lines and also in Fig. 3. As roller d raises the end of the bridge slowly,.the latter is tilted about the central supporting trunnion s, its other end t bearing against the corresponding end` support e. In this position the load is transmitted from the bottom flange of the bridgegirder through the supporting roller d, its

trunnions c, the roller-bearings b and the eccentric discs a or their rails fr to the foundations.

To relieve the parts from the great strain, arrangement has been made to continue the movement of the eccentric discs, which movement results in the supporting roller d being again slightly lowered, t-he roller coming to rest with a cam g (Fig. l) on a support p provided intermediate the rails r, and as the movement is still slightly continued, the discs a now revolve a little about the trunnions c of the supporting roller el thereby being slightly lifted off the rails. The load now is transmitted direct through roller d to the support p and the foundation.

The rotation of the shaft Z and thereby the pinions m for moving the racks i'is effected from the shaft o by means of the spur wheels w and ai Figs. l and 2). The driving power for rotating shaft o is preferably supplied by an electric motor. Obviously, the thrustrods g may also be actuated in any other suitable manner.

I claim:

l. In lifting machinery, two parallel tracks, rolling disks movable therealong, means for positively moving said disks in either direction, a rotatable shaft eccentrically mounted in said disks, and a lifting member carried by said shaft intermediate said disks so as to be moved therewith from a lower to a higher position, and vice versa.

2. The combination as specified in claim l, including a support located intermediate said tracks so as to constitute a rest for said lifting:r member in its linal lifting position.

In testimony whereof I aiX my signature.

FRIEDRICH DUV'E. 

